longPress로 테이블 셀 이동하기

UITableViewCell을 longPress를 이용해서 순서를 바꾸는 방법을 정리

 

1. tableView에 longPress recognizer를 추가한다.
2. longPress의 상태에 따라 동작을 실행한다.
1. 공통 : 제스쳐의 위치값을 가져와 선택한 셀이 무엇인지 얻어온다.
2. Began :  선택한 셀을 복사해서 화면에 노출시킨 귀 본래의 셀은 hidden 상태로 바꾼다.
3. Changed : tableView의 moveRowAtIndexPath 메소드를 이용해 위치를 바꿔준다.
4. default : 복제된 뷰를 제거하고 본래의 셀의 hidden 상태를 해제한다.
3. 완료

 

class TableReorderViewController: UITableViewController {
    
    var data: [Int] = []
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        data = [
            1,2,3,4,5,6,7,9,10,
            11,12,13,14,15,16,17,19,20,
            21,22,23,24,25,26,27,29,30,
            31,32,33,34,35,36,37,39,40
        ]
        
        self.tableView.allowsSelection = false
        
        var longPress = UILongPressGestureRecognizer(target: self, action: "longPressGesture:")
        self.view.addGestureRecognizer(longPress)
    }
    
    override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as UITableViewCell
        
        let entry = data[indexPath.row]
        
        cell.textLabel?.text = "#\(entry)"
        return cell
    }
    
    override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return data.count
    }
    
    // longPress move
    private var sourceIndexPath: NSIndexPath!
    private var cellSnapshot: UIView!
    
    func longPressGesture(sender: UILongPressGestureRecognizer) {
        
        let point = sender.locationInView(self.tableView)
        if let indexPath = self.tableView.indexPathForRowAtPoint(point) {
            if let cell = self.tableView.cellForRowAtIndexPath(indexPath) {
                switch (sender.state) {
                case .Began:
                    sourceIndexPath = indexPath
                    cellSnapshot = self.customSnapshotFromView(cell)
                    self.view.addSubview(cellSnapshot)
                    
                    cellSnapshot.center = cell.center
                    cellSnapshot.alpha = 0.0
                    
                    UIView.animateWithDuration(0.2, animations: { () -> Void in
                        self.cellSnapshot.alpha = 0.9
                        self.cellSnapshot.transform = CGAffineTransformMakeScale(1.05, 1.05)
                    }, completion: { (flag) -> Void in
                        cell.hidden = true
                    })
     
                case .Changed:
                    self.tableView.moveRowAtIndexPath(sourceIndexPath, toIndexPath: indexPath)
                    sourceIndexPath = indexPath
                    
                    var center = cellSnapshot.center
                    center.y = point.y
                    cellSnapshot.center = center
                    
                default:
                    cell.alpha = 0.0
                    cell.hidden = false
                    
                    UIView.animateWithDuration(0.2, animations: { () -> Void in
                        self.cellSnapshot.transform = CGAffineTransformIdentity
                        self.cellSnapshot.center = cell.center
                        self.cellSnapshot.alpha = 0.0
                        cell.alpha = 1.0
                    }, completion: { (flag) -> Void in
                        cell.alpha = 1.0
                        self.cellSnapshot.removeFromSuperview()
                    })

                }
            }
        }
    }
    
    private func customSnapshotFromView(sourceView: UIView) -> UIView {
        UIGraphicsBeginImageContextWithOptions(sourceView.bounds.size, false, 0)
        sourceView.layer.renderInContext(UIGraphicsGetCurrentContext())
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        
        let snapshot = UIImageView(image: image)
        snapshot.layer.cornerRadius = 0.0
        snapshot.layer.shadowOffset = CGSizeMake(-5.0, 0.0)
        snapshot.layer.shadowRadius = 3.5
        snapshot.layer.shadowOpacity = 0.3
        return snapshot
    }
    
}